"RMD not required" was checked and further input is blocked. In any case it does not make sense that Form 1040 Box 4a = 0 and 4b = the 1099R taxable amount.
This is an amount recontributed in 2020 prior to the August 31, 2020 deadline as allowed under the Cares Act to same IRA for 100% of RMD previously distributed ...